Alexander H. Slocum

Learn More
We discuss the rapid growth of films and lithographically templated microstructures of vertically aligned small-diameter multiwalled carbon nanotubes (VA-MWNTs), by atmospheric-pressure thermal chemical vapor deposition (CVD) of C2H4/H2/Ar on a Fe/Al2O3 catalyst film deposited by electron beam evaporation. The structures grow to 1 mm height in 15 min and(More)
This paper reports the design, fabrication and testing of a thermally-actuated bistable MEMS relay. Mechanical bis tability ensures zero actuation power in both the on and off states, and permits actuation with a transient thermal actuator. In the off state, this relay stands off more than 200 V. In the on state, it exhibits a minimum total resistance of 60(More)
Insertion of trocars, needles, and catheters into unintended tissues or tissue compartments results in hundreds of thousands of complications annually. Current methods for blood vessel cannulation or epidural, chest tube, and initial trocar placement often involve the blind pass of a needle through several layers of tissue and generally rely on(More)
This paper describes Robopsy, an economical, patient-mounted, telerobotic, needle guidance and insertion system, that enables faster, more accurate targeting during CT-guided biopsies and other percutaneous interventions. The current state of the art imaging technology facilitates precise location of sites within the body; however, there is no mechanical(More)
Sub-micron alignment for wafer bonding applications has become a major limitation in the development of multi-wafer MEMS devices and 3D interconnects [1,2]. Most wafer alignment is done by mechanically positioning one wafer with respect to another using optical measurement techniques, but the large structural loop makes alignment better than one micron(More)
— The focus of this paper is on the design and evaluation of a robust drive mechanism intended to robotically steer a thermal ablation electrode or similar percutaneous instrument. We present the design of an improved screw-spline drive mechanism based on a profiled threaded shaft and nut that reduces the part count and simplifies manufacturing and(More)
The exceptional electronic, thermal, and mechanical properties of carbon nanotubes (CNTs) have motivated extensive research on their manufacturing and applications. At bulk scales, there is particular interest in property enhancements by adding CNTs to polymers to make composite materials. Most work on CNT-based composites presented in the literature to(More)
We demonstrate that a film of vertically aligned multiwall carbon nanotubes (CNTs) can exert mechanical energy as it grows, and in our experiments the average force output is approximately 0.16 nN per CNT, for CNTs having an outer diameter of 9 nm and five walls. The film thickness after a fixed growth time and the alignment of CNTs within the film decrease(More)